Drystone

Dry stone, sometimes called drystack or, in Scotland, drystane, is a building method by which structures are constructed from stones without any mortar to bind them together. A certain amount of binding is obtained through the use of carefully selected interlocking stones.

Dry stone construction is best known in the context of stone walls, traditionally used for the boundaries of fields and churchyards, or as retaining walls for terracing, but dry stone shelters, houses and other structures also exist. The term tends not to be used for the many historic styles which used precisely-shaped stone, but did not use mortar, for example the Greek temple and Inca architecture.

The art of dry stone walling was inscribed in 2018 on the UNESCO representative list of the intangible cultural heritage of humanity, for dry stone walls in countries such as France, Greece, Italy, Slovenia, Croatia, Switzerland and Spain. In 2024, Ireland was added to the list.

History

Some dry stone wall constructions in north-west Europe have been dated back to the Neolithic Age. In County Mayo, Ireland, an entire field system made from dry stone walls, since covered in peat, has been carbon-dated to 3800 BC. These are near contemporary with the, dry stone constructed, neolithic village of Skara Brae, and the Chambered cairn of Scotland.

The cyclopean walls of the acropolis of Mycenae, Greece, have been dated to 1350 BC and those of Tiryns slightly earlier.
Similar example is Daorson, in Bosnia, built around a prehistoric central fortified settlement or acropolis (existed there c. 17–16th C. BCE to the end of the Bronze Age, c. 9–8th C. BCE), and surrounded by cyclopean walls (similar to Mycenae) dated to the 4th C. BCE.

In Belize, the Mayan ruins at Lubaantun illustrate use of dry stone construction in architecture of the 8th and 9th centuries AD.

Great Zimbabwe in Zimbabwe, Africa, is an acropolis-like large city complex constructed in dry stone from the 11th to the 15th centuries AD. It is the largest of structures of similar construction throughout the area.

Location and terminology

Terminology varies regionally. When used as field boundaries, dry stone structures are more commonly known as dykes in Scotland, where professional dry stone wall builders are referred to as 'dykers'. Dry stone walls are characteristic of upland areas of Britain and Ireland where rock forms natural outcrops or large stones exist in quantity in the soil. They are especially abundant in the West of Ireland, particularly Connemara. They may also be found throughout the Mediterranean, including retaining walls used for terracing. Such constructions are common where large stones are plentiful (for example, in The Burren) or conditions are too harsh for hedges capable of retaining livestock to be grown as reliable field boundaries. Many thousands of kilometres of such walls exist, most of them centuries old.

In the United States they are common in areas with rocky soils, such as New England, New York, New Jersey, and Pennsylvania. They are a notable characteristic of the bluegrass region of central Kentucky, the Ozarks of Arkansas and Missouri, as well as Virginia, where they are usually referred to as ''rock fences'' or ''stone fences'', and the Napa Valley in north central California. The technique of construction was brought to America primarily by English and Scots-Irish immigrants. The technique was also taken to Australia (principally western Victoria, some parts of Tasmania, and some parts of New South Wales, particularly around Kiama) and New Zealand (especially Otago).

Similar walls also are found in the Swiss–Italian border region, where they are often used to enclose the open space under large natural boulders or outcrops.

The higher-lying rock-rich fields and pastures in Bohemia's south-western border range of Šumava (e.g. around the mountain river of Vydra) are often lined by dry stone walls built of field-stones removed from the arable or cultural land. They serve both as cattle/sheep fences and the lot's borders. Sometimes also the dry stone terracing is apparent, often combined with parts of stone masonry (house foundations and shed walls) that are held together by a clay and pine needle "composite" mortar.

The dry stone walling tradition of Croatia was added to the UNESCO Representative List of the Intangible Cultural Heritage of Humanity in November 2018, alongside those of Cyprus, France, Greece, Italy, Slovenia, Spain and Switzerland. In Croatia, dry stone walls () were built for a variety of reasons: to clear the earth of stone for crops; to delineate land ownership; or for shelter against the bora wind. Some walls date back to the Liburnian era. Notable examples include the island of Baljenac, which has of dry stone walls despite being only in area, and the vineyards of Primošten.

Sauvignargues 535.jpg, "Cabane de Malais" at Souvignargues, Gard